Mobilizing Host Cells for In-Body Tissue Regeneration

Is it possible to control the body’s natural reparative powers so that tissue can be regenerated from within – rather than engineering replacement tissue in the lab?

Is it well known that the body has regenerative powers that can heal a small injury. Larger injuries, however, result in the formation of scar tissue that reduces function. Our study, reported in Rejuvenation Research, addressed the question of whether the repair process can be controlled to regenerate tissue, rather than result in scarring.

Our first step was to establish if the cells that rush to the site of an injury have the capacity for regeneration. We implanted a common biomaterial in mice and found that infiltrating cells are not entirely comprised of the inflammatory and fibroblast-like cells that form scar tissue, as was previously assumed.

Instead, the infiltrating cells are capable of differentiating into multiple cell lineages, including bone, muscle, fat and blood vessel cells if appropriate conditions are provided. These results indicate that the fate of these cells can be controlled so that they become specific cells types needed for the regeneration of functional tissue.

These findings suggest the possibility of developing tissue-specific biomaterials that could be applied to any patient without the need to grow tissue outside the body. For example, to repair a muscle injury, a biomaterial designed to attract muscle-producing cells, could be implanted at the site. The patient’s body would provide both the source of the cells and the environment for attracting them.

(Host cell mobilization for in situ tissue regeneration. Lee SJ, Van Dyke M, Atala A, Yoo JJ. Rejuvenation Res. 2008 Aug; 11(4):747-56.)